1. Field of the Invention
The present invention relates to a resist pattern forming method, a semiconductor apparatus using said method, and an exposure apparatus thereof, and more particularly to a method for forming a resist pattern by exposing a resist film formed on a substrate through a liquid in order to form a latent image and then performing selective development, and a semiconductor apparatus using the method, and an exposure apparatus thereof.
2. Description of the Related Art
An immersion exposure apparatus employs a technique which performs exposure by filling a liquid between a resist film surface and a lens of an exposure apparatus when a resist film formed on a substrate in process is exposed. As apparatuses used in such an exposure method, there is an apparatus disclosed in, e.g., Jpn. Pat. Appln. KOKAI Publication No. 10-303114. This patent reference discloses an apparatus, which has a stage capable of supplying water, immerses an entire substrate in water and performs exposure while relatively moving the stage with respect to the exposure apparatus. In the apparatus having such a conformation, since a liquid is supplied to the entire stage, there is a problem that liquid spills from the stage when the stage moves at a high speed, making a high-speed driving hard.
As a countermeasure for a disturbance of a liquid flow due to movement of the stage, a technique which drives the stage while locally supplying liquid to a part being exposed is disclosed in “Immersion lithography; its potential performance and issues,” Proc. of SPIE Vol. 5040, pp. 724-733, by Soichi Owa and Hiroyuki Nagasaka. The stage can be moved at a high speed by the technique disclosed in the reference. When such a technique of locally supplying liquid is used, there are problems that water remains in an exposure area or the like in a part from which a lens is gone, and if performing post-exposure heating to the resist film in such a state, then a water mark and/or a resist pattern defect due to insufficient temperature are generated at the part where the water has remained, for example.
Further, when performing exposure near an edge of a substrate, water may flow to an edge portion of a resist film in some cases. In such a case, a turbulent in water flow is generated at step between the substrate and the edge of the resist film, and an air bubble can be caught. When the air bubble reaches an exposure slit area, an exposure trouble may possibly occur in some cases. There is a problem that a resist pattern defect is generated due to the exposure trouble.
Therefore, in the immersion exposure which performs exposure through the liquid film formed in a local area on the substrate, there is need for a resist pattern forming method which can suppress an occurrence of a defect in a resist pattern.